If you buy a Nokia Internet Tablet and you think there is something wrong with it you can exercise your customer rights - business as usual in the consumer electronics industry. Filing bugs and get them eventually fixed in updates goes in addition to (and not instead of) the guarantee of the product.
And if it gets fixed unofficially, would that be good enough? Assuming we can get a decent-ish Diablo-on-steroids out, you'll have a far better chance of fixing any problems you see yourself, or persuading others that they are important and fixing them en-mass.
I can (sort of) understand your frustration (though I have various devices that have limitations/problems which get very very infrequent firmware updates, which usually cause more problems than they solve too).